ARTICLES

Thunderstorms form when the three required atmospheric conditions of sufficient moisture, unstable air and a lifting mechanism are present. In the United States, thunderstorms are most common in the spring and summer mon...

www.reference.com/article/causes-thunderstorms-15a9c54afc45897e

Thunderstorms are formed by the combination of three main ingredients: moisture, unstable atmospheric air and an external acting force making the damp and volatile air rise upward. Thunderstorms come in several different...

www.reference.com/article/causes-thunderstorm-87036a30dbb5827f

The causes of westward expansion were the purchase of the Louisiana territory from France, the Lewis and Clark expedition, President Thomas Jefferson's vision of expanding into the available land to create an "empire of ...

www.reference.com/history/cause-effect-westward-expansion-ebb4e06bcf0bd4ee

SIMILAR ARTICLES

Tornadoes form out of thunderstorms, where moist air rises, cools and condenses into clouds that release heat and force cooler air back down. If the updrafts are strong enough, the feedback loop forms an air vortex that ...

www.reference.com/article/happens-during-tornado-68884299acd81d54

Most tornadoes are created as a result of thunderstorms that form at the meeting point between humid air from the Gulf of Mexico and dry, cooler air from Canada. At that point, instability occurs in the atmosphere, and a...

www.reference.com/article/simple-terms-tornado-created-f7efb2b0f30492a9

Hurricanes are massive storms made out of an organized series of thunderstorms that form over the ocean. Typhoons are the same as hurricanes, except they occur in a different part of the world. Tornadoes are smaller stor...

www.reference.com/article/hurricanes-tornadoes-typhoons-different-67689aaccccef7ed

Hurricanes form over warm ocean water when the air is cooler above. Winds must be at the surface of the ocean and spiral air inward for the hurricane to form.

www.reference.com/article/hurricanes-8ffda7798ad9154b